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“A special shape of a háček, similar to an apostrophe, is used in Czech and Slovak with ď, ľ, Ľ and ť characters. It could be derived from the apostrophe or comma, but it should be more humble, smaller, and, importantly, narrower. Generally, the symbol should draw less attention than the comma.”

While this doesn't entirely answer your question, it may be a useful resource if you aren't already familiar with it.

I too would be interested in knowing which languages use the single characters, but then also know whether or not users actually type out the correct character or opt for the apostrophe hack.

I'd like to know of a tool that can answer such questions. I downloaded in May a file Crubadan.csv that contains in a jsondata field called "boundary" (whose meaning is unclear to me) those characters for the following languages

ďľ and ť are distinct letters and are used primarily in Czech (ďť) and Slovak (ďľť).

Ondrej Jób’s Context of Diacritics site is a good source for finding combinations that may need special spacing/kerning attention.

d’l’ and t’ are letters (dlt) followed by an apostrophe (’). The apostrophe is used in many languages for various reasons. In English, it is used for the possessive, so you can find just about any letter followed by ’s. In many languages (including English) the apostrophe can be used to indicate an abbreviation. It can also sometimes be used for transliterating palatalization or marking nasality. Read more at Wikipedia: https://en.wikipedia.org/wiki/Apostrophe#Non-English_use

So, you can encounter those apostrophe combinations in many, many languages. You should just space the apostrophe accordingly.

d’ and l’ (with apostrophe) are particularly common in French, Italian, and some related Romance languages. These are abbreviations of the end of common articles such as de, da, le, la, delle, della, etc., usually when followed by another vowel, as in dell’arte.

What's important to note is that these articles can appear with lowercase followed by uppercase — as in Joan d’Arc.

One common novice mistake is to kern the ’A too tight, such that d’A and l’A crash together. Even trickier is L’A, since it requires balancing the L’ and the ’A kern values.

Note also that orthographies that use the apostrophe sign as a letter, rather than as punctuation, may encode this as U+02BC ʼ MODIFIER LETTER APOSTROPHE. This is typically identical in form to the apostrophe (U+2019), but may behave differently in some situations, including typographic variants such as smallcaps.